1. Field of the Invention
The present invention relates to a continuous process for dyeing textile thread, particularly thread of synthetic fibers, by impregnation of this thread by means of a dye solution constituted of at least one base colorant dissolved in an appropriate solvent, process in which the thread is passed continuously through an impregnation enclosure containing said solution, then through at least one enclosure for water extraction by compressed air in which one collects a liquid residue from water extraction.
The present invention relates likewise to an installation for the implementation of the process, comprising at least one impregnation enclosure followed by at least one water extraction enclosure, means to pass a textile thread continuously through said enclosures, and a circuit of dye solution passing into the impregnation enclosure and provided with recovery means under this enclosure and under the water extraction enclosure.
2. Discussion of Background and Relevant Information
One of technique for continuously dyeing textile threads is described in the French patent application published under the number 2,429,288 and include passing the threads into at least one dye bath contained in at least one tank fed with dye solution. These tanks usually contain a relatively significant volume of dye solution, to avoid a too rapid decrease in the dye bath. The "correction" of the bath is carried out generally periodically, by manual addition of base colorants, possibly followed by a colorimetric control.
These tanks are constantly fed with new dye solution to compensate for the used portion, and in practice operate at a constant level.
In the technologies using dye baths in which one soaks the threads on reels or skeins, the bath ratio is currently from 1 to 10, i.e. that for 100 Kg of treated products, the bath must Contain approximately 1000 Kg of dye solution. Given that the base colorant is expensive, this technique which is not economical, also poses the ecological problem of evacuation of the remaining solution.
All of the prior techniques have numerous disadvantages that both include economical and technical considerations.